I second the praise given by the first reviewer. This is a beautiful resource, as portable as your phone.
I wanted the atlas for my smartphone, a Nokia E71, Symbian 60-3, and found the following:
The resolution of the epub* is too low for usability. The pdf will open but at 16.9 Mb, the file is unwieldy, very slow to open and almost impossible to navigate.
The solution is found by clicking the HTTP 'all files' link. Download the jp2.zip
archive, where each chart is accessible separately.
*[I recommend the freeware application Albite Reader for epub files in general. It was crafted and is updated very much in the spirit of this wonderful library.]